ral ssBioMed CentBMC Ecology Open AcceResearch article Patterns of genetic structuring in the coral Pocillopora damicornis on reefs in East Africa

Background: Studies of population genetic structures provide an indication of direction and magnitude of larval transport and hence are an important component in the assessment of the ability of reefs to recover from severe disturbance. This paper reports data on population genetic structures in the coral Pocillopora damicornis from 26 reefs in Kenya and Tanzania. Results: Gene flow among reefs was found to be variable, with a significant overall genetic subdivision (FST = 0.023 ± 0.004 SE; p < 0.001), however, only 34 % of all pairwise population comparisons showed significant differentiation. Panmixia could not be rejected between reefs separated by as much as 697 km, while other sites, separated by only a single kilometre, were found to be significantly differentiated. An analysis of molecular variance indicated that population genetic differentiation was significant only at the smaller spatial scale (< 10 km), whereas panmixia could not be rejected between groups of samples separated by over 100 km. Estimates of contemporary gene flow showed similar results, with numbers of first generation migrants within each population ranging from 0 to 4 (~5 % of the total number of colonies sampled) and likely dispersal distances ranging between 5 and 500 km